Abstract
In this research work, we use high density plasma chemical vapor deposition system to fabricate uc-Si/poly-Si films, and study the crystallinity and doping characteristics affected by adjustable process parameters, hydrogen dilution ratio, RF power, process pressure, substrate temperature, substrate biasing, doping gas flow rate, and finally analyze by XRD, SEM, Hall Measurement etc.In our research, we find the anomalous effect by hydrogen dilution ratio different from amount references, here we got the amorphous Si at dilution ratio at 99%, and poly-Si at lower dilution ratio, the lower hydrogen dilution ratio will result better crystallinity. Also we discover the doping gas flow rate will affect no matter the crystallinity or doping concentration. In our experiment, we got remarkable doping concentration at lower gas doping flow rate, 0.2sccm, and the crystallinity is only observed at this flow rate.We also focus on getting better doping concentration for N-type and P-type. As other references, n-type doping is easier than p-type. In our experiment, we got doping concentration 9 x 1018cm-3 at RF power 1000W，5.3x1015cm-3 at 900W for p-type；and 3 x 1020cm-3 at even lower than 900W for n-type, but in order to get higher doping concentration, lower doping gas flow rate is necessary.